Inclusion / exclusion criteria. Twenty-five patients diagnosed with unilateral or bilateral OA of the hip will be recruited from the Norwegian Sport Medicine Centre, Diakonhjemmet and from the Orthopaedic Centre, Ullevål University Hospital, Oslo, Norway. PPatients will also be recruited through ads in newspaper and brief information in national tv. Radiographiccally verified OA of the hip will be in accordance with Danielsson's criteria for minimal joint space. Patients will be excluded if they have a history of resent trauma or functional impairment to the lower limbs or diseases which might interfere with participation.